JP6507902B2 - Wireless positioning map generation system - Google Patents

Description

  The present invention relates to a wireless positioning map generation system that generates a wireless positioning map, which is a map used when determining the position of a mobile based on radio waves received by a wireless positioning device used by the mobile.

  Conventionally, as described in Patent Document 1, there is known a wireless positioning device which measures the position of a moving object by using a wireless communication device which is mounted on a moving object and receives radio waves from a base station. The wireless positioning device generates a trajectory (hereinafter, reception intensity trajectory) representing the relationship between the moving distance of the moving object and the reception intensity of radio waves received from the base station by the wireless communication device mounted on the moving object. The position of the mobile body is estimated by matching this received intensity locus with a previously prepared received map.

  Specifically, in Patent Document 1, positioning target coordinates are determined in advance for one or more feature points having features in the reception map. In the reception map, a part having a high matching with the reception intensity locus is extracted, and the relative position between the feature point present in the extracted part and the end of the reception intensity locus is determined. Then, based on the position information of the feature point and the relative position between the feature point and the end of the reception intensity locus, the current position of the moving object located at the end of the reception intensity locus is determined in the positioning target coordinate system.

  Note that the reception map is a wireless positioning map, and the wireless positioning map is hereinafter referred to as a reception map.

JP, 2013-257306, A

  In the prior art, feature points need to be present in the reception map. However, depending on the installation environment of the base station, there may be no clear feature point. In addition, when the feature points do not exist at appropriate intervals, there is a problem that the current position can not be accurately correlated with the point on the map represented in the positioning target coordinate system.

  Here, it is conceivable to create the correspondence between the relative coordinates and the positioning target coordinates so that the correspondence between the relative coordinates of the reception map and the positioning target coordinates is determined at an arbitrary point on the reception map.

  In this correspondence, it is not necessary to define positioning target coordinates for all relative coordinates on the reception map. If positioning target coordinates are defined with respect to relative coordinates at intervals determined according to positioning accuracy, positioning target coordinates are determined by interpolation even for relative coordinates for which positioning target coordinates are not defined for correspondence. be able to.

  However, even if the positioning target coordinates do not need to be defined for all relative coordinates on the reception map, the larger the reception map, the more correspondence between the relative coordinates and the positioning target coordinates becomes necessary. Therefore, in a region where positioning of positioning target coordinates is difficult, there is a risk that a continuous reception map can not be created over a wide area.

  The present invention has been made under the above circumstances, and an object thereof is to provide a wireless positioning map generation system capable of generating continuous reception maps over a wide area.

  The above object is achieved by a combination of the features of the independent claims, and the subclaims define further advantageous embodiments of the invention. The reference numerals in parentheses described in the claims indicate the correspondence with the specific means described in the embodiment described later as one embodiment, and do not limit the technical scope of the present invention .

According to a first aspect of the present invention for achieving the above object, there is provided a reception state indicator which represents a reception state of radio waves when radio waves from a base station are received on the path with respect to a position along a path along which the mobile body can move. A radio positioning map generation system that generates a reception map that represents a change and that can represent the position in the direction along the route in the positioning target coordinate system,
A storage unit (42) which stores the reception map in a rewritable manner;
A distance measuring unit (361) for measuring the moving distance of the moving body,
An indicator measurement unit (31) that receives radio waves from the base station and measures the reception condition indicator sequentially when the mobile is moving;
A trajectory generation unit (363) for generating a reception state trajectory representing a relationship between the movement distance measured by the distance measurement unit and the reception condition indicator measured by the indicator measurement unit;
A map updating unit that updates the reception map stored in the storage unit by combining the reception state trajectory generated by the trajectory generation unit and the reception map stored in the storage unit based on the mutual matching part S2, S4, S6, S12, 433) ,
The map update unit combines the reception state trajectory generated by the trajectory generation unit and the reception map stored in the storage unit in the direction along the route based on the mutual matching portion, and stores it in the storage unit. The reception state trajectory generated by the trajectory generation unit is updated while performing trajectory correction that is at least one of relative movement and expansion / contraction in the direction of movement distance. If it is determined that there is a match between the reception maps stored in the storage unit, and if it is determined that there is a match, the reception state trajectory after trajectory correction is combined with the reception map stored in the storage unit. ,
Whether or not there is a locus-side distance test point at which the relative distance in the positioning target coordinate system between the reception state track and the map-side distance test point which is a point on the reception map stored in the storage unit can be determined A test point judging unit (S8) to judge;
When the test point determination unit determines that there is a trajectory side distance test point, after performing trajectory correction on the reception state trajectory, the point moved by the relative distance from the relative coordinates of the map side distance test point And a distance difference determination unit (S10) for determining whether the distance difference between the relative coordinates and the relative coordinates of the trajectory-side distance test point is within a predetermined range.
The map updating unit updates the reception map stored in the storage unit based on the fact that the distance difference judging unit judges that the distance difference is within the predetermined range, and the distance difference judging unit judges that the distance difference is predetermined. It is characterized in that the reception map stored in the storage unit is not updated based on the judgment that it is not within the range .
The second invention is
It represents the change in the reception state indicator that represents the reception state of radio waves when radio waves from the base station are received on the route with respect to the position in the direction along which the mobile body can move. A wireless positioning map generation system for generating a reception map that can represent a position in a positioning target coordinate system,
A storage unit (42) which stores the reception map in a rewritable manner;
A distance measuring unit (361) for measuring the moving distance of the moving body,
An indicator measurement unit (31) that receives radio waves from the base station and measures the reception condition indicator sequentially when the mobile is moving;
A trajectory generation unit (363) for generating a reception state trajectory representing a relationship between the movement distance measured by the distance measurement unit and the reception condition indicator measured by the indicator measurement unit;
A map updating unit that updates the reception map stored in the storage unit by combining the reception state trajectory generated by the trajectory generation unit and the reception map stored in the storage unit based on the mutual matching part S2, S4, S6, S12, 433),
The moving body is a vehicle,
In addition to the reception map, the route direction position which is the position along the route on the reception map is associated with the width direction position on the road where the reception condition index corresponding to the route direction position on the reception map can be measured A map generation system for wireless positioning that generates a width direction position map,
The storage unit stores the width direction position map in addition to the reception map,
A width direction position detection unit (131) for detecting a width direction position of the vehicle;
A width direction locus generation unit (366) for generating a width direction position locus indicating a relationship between the movement distance measured by the distance measurement unit and the width direction position detected by the width direction position detection unit;
By moving the width direction position locus generated by the width direction locus generation unit in the longitudinal direction of the road and moving the reception state locus by the same amount as the width direction position locus in the longitudinal direction of the road, And a match determination unit (432) for determining whether the width direction position map has a match with each other and the reception state trajectory and the reception map also have a match with each other.
The map update unit (433) determines that the match determination unit generates a match between the width direction position track and the width direction position map and that the reception state route and the reception map also match each other. Based on the above, the width direction position locus in the state where the width direction position locus and the width direction position map coincide in the matching portion is combined with the width direction position map, and the width direction position map stored in the storage unit is updated. In addition, the reception state locus in the state where the reception state locus and the reception map coincide with each other in the coincidence portion is coupled to the reception map, and the reception map stored in the storage unit is updated.

  According to the present invention, when the mobile is moving, a reception state locus is generated, and the reception state locus is combined with the reception map stored in the storage unit based on the matching parts. As a result, since the reception map spreads, it is possible to generate a continuous reception map over a wide area.

It is a block diagram of the wireless positioning system 10 of 1st Embodiment. It is a block diagram which shows the internal structure of the wireless positioning device 30 of FIG. It is a block diagram which shows the function of the control part 36 of FIG. It is a figure which shows an example of the probe locus | trajectory which the locus | trajectory production | generation part 363 of FIG. 3 produces | generates. It is a figure which shows an example of a reception map. It is a block diagram which shows the internal structure of the management server 40 of FIG. It is a flowchart which shows the process which the control part 44 of FIG. 6 performs. It is a figure explaining the process of FIG.7 S4. It is a figure which compares and shows the probe locus | trajectory A before locus | trajectory correction | amendment, and the probe locus | trajectory Ac after locus | trajectory correction | amendment. It is a figure explaining the process of FIG.7 S10. FIG. 6 is a diagram for explaining coupling of a probe trajectory A and a probe trajectory J to a reception map B. It is a figure which shows the receiving map after combining the probe locus | trajectory A and the probe locus | trajectory J to the receiving map B. FIG. It is a block diagram which shows the internal structure of the wireless positioning device 130 in 2nd Embodiment. It is a block diagram which shows the function of the control part 36 of FIG. It is a figure which shows notionally the width direction position locus | trajectory which the width direction locus | trajectory production | generation part 366 produces | generates. It is a block diagram which shows the function with which the control part 44 of the management server 40 is provided in 2nd Embodiment. It is a figure which illustrates the receiving map and width direction position map which are stored in receiving map database 43 in a 2nd embodiment. It is a figure which shows a probe locus | trajectory and a reception map, and a width direction position locus | trajectory and a width direction position map by the same horizontal axis. FIG. 19 is a diagram showing a state in which the probe locus and the width direction position locus are moved from the state of FIG. 18 so as to produce a matching part with the reception map and the width direction position map. FIG. 14 is a diagram showing a reception map and a width direction position map which are sequentially added in the third embodiment. It is a figure which illustrates the width direction receiving map WR produced | generated in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described based on the drawings.

First Embodiment
[Overview of Configuration of Wireless Positioning System 10]
The wireless positioning system 10 of the first embodiment also has a function as a wireless positioning map generation system. As shown in FIG. 1, the wireless positioning system 10 includes a base station 20, a plurality of (two in FIG. 1) wireless positioning devices 30, and a management server 40.

  Although only one base station 20 is shown in FIG. 1, the base station 20 is installed for each position estimation area where position estimation using the wireless positioning device 30 is performed. The size of the position estimation area means the size of the communication area of the base station 20.

  The base station 20 periodically transmits radio waves within the communication area of the base station 20 with a constant transmission power. The radio waves transmitted by the base station 20 are hereinafter referred to as base station radio waves. The information transmitted by the base station radio wave is not particularly limited, and is, for example, information including identification information of the base station 20.

  The base station 20 is, for example, a communication device (hereinafter referred to as a roadside device) installed on the roadside. The roadside aircraft may be installed in an area out of reach of radio waves from the navigation satellites provided in the Global Navigation Satellite System (GNSS). Alternatively, a broadcast station such as a radio station or a television station can be used as the base station 20. When the roadside unit is the base station 20, the position estimation area is, for example, several hundred meters in radius. If the broadcasting station is the base station 20, the position estimation area may be, for example, several tens of kilometers in radius.

  The method of transmitting base station radio waves may be transmission that does not specify a communication partner, that is, may be broadcast, or may be a method of specifying a communication partner. Note that communication in the present specification also includes communication by a broadcast system.

  Direct communication and relay communication can be used in any of the communication by the broadcast system and the system for specifying the communication partner. Direct communication means performing communication without passing through another device such as a relay station. Relay communication is communication using a retransmission facility.

  Further, the base station 20 is configured to be communicable with the management server 40 via a wide area wireless communication network NW such as a cellular phone communication network.

  The wireless positioning device 30 is mounted on a vehicle 50 which is a moving object, generates a probe trajectory to be described later, and based on a comparison between the probe trajectory and a reception map acquired from the management server 40, the wireless positioning device 30. Estimates the current position of the vehicle 50 (hereinafter referred to as own vehicle) on which the vehicle is mounted. The wireless positioning device 30 performs direct wireless communication with the base station 20 and communicates with the management server 40 via the wide area wireless communication network NW.

  The management server 40 manages a reception map used to estimate the current position of the wireless positioning device 30. Specifically, the management server 40 generates and updates the reception map, and transmits the reception map to the wireless positioning device 30. Note that this reception map may be transmitted to the wireless positioning device 30 via the base station 20.

[Configuration of Wireless Positioning Device 30]
As shown in FIG. 2, the wireless positioning device 30 includes a wireless communication device 31, a vehicle speed sensor 32, a wide-area wireless communication device 33, a positioning unit 34, a memory 35, and a control unit 36.

  The wireless communication device 31 receives a base station radio wave. Then, it demodulates and decodes the received base station radio wave and outputs it to the control unit 36. Also, the received signal strength indicator of the base station radio wave (Received Signal Strength Indicator) is sequentially measured, and the measured received signal strength is output to the control unit 36. The received signal strength is hereinafter referred to as RSSI. The RSSI corresponds to the reception status indicator in the claims, and the wireless communication device 31 corresponds to the indicator measurement unit in the claims.

  The vehicle speed sensor 32 detects the speed of the host vehicle, that is, the vehicle speed. The vehicle speed detected by the vehicle speed sensor 32 is input to the control unit 36. The vehicle speed sensor 32 is a sensor for calculating the positional change of the vehicle 50 based on an arbitrary time, that is, the movement distance x of the vehicle 50 based on the position of the vehicle 50 at an arbitrary time. Since the vehicle 50 travels on the road, the travel distance x is a travel distance x on the road on which the vehicle 50 can travel.

  The wide area wireless communication device 33 communicates with the management server 40 via the wide area wireless communication network NW. The positioning unit 34 includes a GNSS receiver that receives radio waves from navigation satellites, which are components of the GNSS. Based on the signal received by the GNSS receiver, absolute coordinates of the current position are detected. Absolute coordinates are represented by latitude PX, longitude PY and altitude PZ. A signal received by the GNSS receiver corresponds to positioning information, an absolute coordinate system corresponds to a positioning target coordinate system in claims, and an absolute coordinate corresponds to a positioning target coordinate.

  The memory 35 is a writable and non-volatile memory, and can store a plurality of reception maps. In the present embodiment, the reception map is generated by the management server 40, transmitted to the wireless positioning device 30, and stored in the memory 35.

  The control unit 36 includes a CPU 37, a ROM 38, and a RAM 39. When the CPU 37 executes a process based on a program stored in the ROM 38, the control unit 36 controls the wireless communication device 31 and the wide area wireless communication device 33.

  Further, as shown in FIG. 3, the control unit 36 also has functions as a distance measurement unit 361, an index acquisition unit 362, a trajectory generation unit 363, a trajectory transmission control unit 364 and a position estimation unit 365. Note that part or all of the functions executed by the control unit 36 may be configured as hardware by one or more ICs or the like.

  The distance measuring unit 361 sequentially acquires the signal detected by the vehicle speed sensor 32, and sequentially measures the moving distance x of the vehicle 50 from an arbitrary time point.

  The index acquisition unit 362 sequentially acquires the RSSI measured by the wireless communication device 31 when the host vehicle is traveling.

  The trajectory generation unit 363 generates a trajectory (hereinafter, probe trajectory) representing the relationship between the movement distance x measured by the distance measurement unit 361 and the RSSI acquired by the index acquisition unit 362. This probe trajectory corresponds to the reception state trajectory.

  FIG. 4 is an example of the probe trajectory, and when the position of the host vehicle changes, the reception environment also changes. Therefore, as shown in FIG. 4, the probe trajectory changes the size of the RSSI according to the change of the movement distance x. The probe trajectory is not a continuous curve, but a set of discrete points, as shown in FIG. This is because the moving distance x and the RSSI can be obtained discretely.

  When there is a point at which absolute coordinates can be determined for any of the points constituting the probe trajectory, the trajectory generation unit 363 associates the absolute coordinates with the movement distance x. FIG. 4 shows an example in which absolute coordinates (PX1, PY1, PZ1) of the point pa are associated with the movement distance x1.

  Note that the point at which the absolute coordinate is determined is not limited to the case where the positioning unit 34 can measure the absolute coordinate at a certain movement distance x, but the absolute coordinate at the movement distance x is interpolated Also includes cases where it can be determined. The point whose absolute coordinate has been determined and the point on the probe trajectory do not exactly match, so they can be included if they can be determined by interpolation. However, depending on the condition of interpolation, the accuracy of the absolute position P corresponding to the movement distance x is lowered, so a condition is set in which an error is allowed. This condition includes, for example, that the difference in distance between the absolute coordinates determined by interpolation and the measured absolute coordinates is equal to or less than a predetermined distance.

  The locus transmission control unit 364 transmits the probe locus generated by the locus generation unit 363 from the wide area wireless communication device 33 to the management server 40. The probe trajectory may be transmitted to the management server 40 via the wireless communication device 31. The timing of transmitting the probe trajectory can be set variously. For example, it may be every constant cycle, or may be a condition that the probe trajectory has become a constant movement distance x.

  The position estimation unit 365 determines whether the reception map stored in the memory 35 includes a portion that matches the probe trajectory generated by the trajectory generation unit 363. In this determination, while moving the probe trajectory in the moving distance direction, it is determined whether or not there is a portion that matches the reception map.

  The reception map is a map in which the horizontal axis is the movement distance x and the vertical axis is the RSSI. An example of the reception map is shown in FIG. The movement distance x means relative coordinates from the origin with an arbitrary point as the origin. Further, the movement distance x in the reception map is associated with absolute coordinates at least at a plurality of points. By interpolating using a plurality of moving distances x associated with absolute coordinates, any point on the reception map can be associated with absolute coordinates. Therefore, the horizontal axis of the reception map may be previously set as absolute coordinates.

  The reception map used by the position estimation unit 365 to determine the presence or absence of a portion that matches the probe trajectory is a reception map whose absolute coordinates are in the area when the area in which the host vehicle is present can be estimated. The area in which the vehicle is present is estimated from the absolute coordinates measured by the positioning unit 34 and the elapsed time since the last movement distance or absolute coordinates were measured.

  When the reception map corresponding to the estimated area is not stored in the memory 35 and the reception map corresponding to the area is stored in the reception map database of the management server 40, the position estimation unit 365 The reception map corresponding to the estimated area is acquired from the management server 40.

  If there is a portion in the receiving map that matches the probe trajectory, the absolute coordinates of the current position are determined from the coordinates of the horizontal axis of the receiving map determined by the end point of the probe trajectory in the state where the probe trajectory matches the receiving map. Do.

  The reason why the position estimation unit 365 estimates the current position of the vehicle despite the positioning unit 34 is that the positioning unit 34 can not always measure the current position, and the current position Even if the positioning can be performed, the positioning accuracy is not necessarily good. That is, when the positioning unit 34 can not measure the current position or when the positioning accuracy is poor, the position estimated by the position estimation unit 365 is set as the current position of the vehicle.

[Configuration of Management Server 40]
As illustrated in FIG. 6, the management server 40 includes a wide area wireless communication device 41, a storage unit 42, and a control unit 44.

  The wide area wireless communication device 41 communicates with the base station 20 and the wireless positioning device 30 via the wide area wireless communication network NW.

  In the storage unit 42, the reception map database 43 is stored so as to be rewritable. The reception map database 43 is a database including a plurality of the reception maps described above. The reason why there are multiple reception maps instead of one is that the vehicle needs to travel and measure RSSI in order to determine the reception map, but measuring RSSI for all roads Because it is impossible. Since it is not possible to measure the RSSI for all roads, the reception map may be cut off along the roads. Therefore, there are a plurality of reception maps. However, the reception map is expanded by combining the probe trajectories transmitted from the wireless positioning device 30.

  Also, the reception map may be generated by a device that generates a reception map and added to the reception map database 43.

  The control unit 44 includes a CPU 45, a ROM 46, and a RAM 47. When the CPU 45 executes a process based on a program stored in the ROM 46, the control unit 44 controls the wide area wireless communication device 41. Manage 43 Furthermore, the control unit 44 periodically executes the process shown in FIG. Note that part or all of the functions executed by the control unit 44 may be configured as hardware by one or more ICs or the like.

[Function of Control Unit 44 of Management Server 40]
In FIG. 7, in step S <b> 2, the wide-area wireless communication device 41 determines whether a probe trajectory has been received from the wireless positioning device 30. If this judgment is NO, processing of Drawing 7 will be ended, and if it is YES, it will progress to Step S4.

  In step S4, it is determined whether the probe trajectory determined to have been received in step S2 includes a portion similar to the reception map already stored in the storage unit 42. This determination can use various known methods for determining shape similarity.

  For example, a cutout range of a predetermined size is cut out from the probe trajectory, and the similarity of the shape with the reception map is determined while moving the probe trajectory of the cutout range in the direction of the movement distance x. The size of the cutout range can be set arbitrarily.

  If it is determined in step S4 that there is a point whose absolute coordinate is associated with the probe trajectory, the arrangement of the probe trajectory relative to the reception map is determined based on the point where the absolute coordinate is associated in the probe trajectory. At the position thus arranged, it is determined whether the probe trajectory includes a portion similar to the reception map already stored in the storage unit 42. By doing this, it is possible to suppress that a portion having a similar shape by chance despite being different in absolute coordinates is made to be a similar portion in this step S4.

  In FIG. 8, the process of step S4 is described by using the probe trajectory illustrated in FIG. 4 and the reception map illustrated in FIG. 5 as an example. In FIG. 8, the probe trajectory is A, and the reception map is B.

  In the probe trajectory A, a point whose movement distance x is x1 is associated with the absolute coordinate PX1. Therefore, the probe locus A is arranged with respect to the reception map B such that the movement distance x1 of the probe locus A becomes the absolute coordinate PX1. In this state, it is determined whether there is a similar part. In the example of FIG. 8, in the probe trajectory A, the part on the right side of the coordinate b0 is a similar part. If the determination in step S4 is NO, the process of FIG. 7 is ended, and if YES, the process proceeds to step S6. Also in the following description, the probe trajectory A and the reception map B are used as appropriate.

  In step S6, the distance C between origins of the following formulas 1 and 2 and the enlargement / reduction coefficient d are determined such that the degree of coincidence of the similar part determined in step S4 is the highest. Then, trajectory correction for correcting the probe trajectory is performed using Equation 2.

In Equation 1, a0 is the movement distance (ie, relative coordinates) of the origin of the probe trajectory Ac after trajectory correction when represented by the horizontal axis coordinate system of the reception map (ie, the relative coordinate system of the reception map). b0 is the origin of the reception map. xa is the value of the movement distance x of an arbitrary point on the probe trajectory A in the relative coordinate system of the probe trajectory A. xa _c is the value of the moving distance x at any point on the probe locus Ac after trajectory correction in reception map relative coordinate system.

Equation 2 expands and reduces the probe trajectory A in the direction of relative movement and movement distance x, and sets any point of the probe trajectory A to a point that constitutes the probe trajectory Ac after trajectory correction in the relative coordinate system of the reception map. Represents an expression to convert.
(Formula 1) a0 = b0 + C
(Formula 2) xa _c = (d × xa) −a 0

  In FIG. 9, the probe locus A before locus correction and the probe locus Ac after locus correction are compared and shown. The probe trajectory A before the trajectory correction is moved upward as shown in FIG. 8 in order to make the probe trajectory A easy to see. In fact, the probe trajectory A before trajectory correction also has the same RSSI as the probe trajectory Ac after trajectory correction.

  As shown in FIG. 9, in the probe trajectory Ac after trajectory correction, the origin a0 is offset from the origin before correction by the offset amount c0. In FIG. 9, L is a moving distance length of the probe trajectory A before correction, and Lc is a moving distance length of the probe trajectory Ac after correction. In this case, the scaling factor d is Lc / L.

  In step S8 corresponding to the test point determination unit, it is determined whether or not the probe trajectory has a point where the relative distance to the point on the reception map can be determined in the absolute coordinate system. In the reception map, since absolute coordinates are determined at an arbitrary point, this determination is YES if there is a point where absolute coordinates are associated with the probe trajectory. In the probe trajectory, a point to which absolute coordinates are associated is referred to as a trajectory-side distance test point. Also, a point on the reception map is called a map side distance test point. If the determination in step S8 is NO, the process of FIG. 7 is ended, and if YES, the process proceeds to step S10.

  In step S10 corresponding to the distance difference determination unit, the relative coordinates of the point moved by the relative distance from the relative coordinates of the map side distance test point and the relative distance with respect to the point on the reception map in the probe locus Ac after locus correction. It is determined whether or not the difference in distance from the relative coordinates of the known point (i.e., the locus-side distance test point) is within a predetermined range.

In the example of FIG. 10, the point pa _c is the trajectory space distance test point, the point pb is mapped side distance test point. The relative coordinates of the point pb (ie, the movement distance x) is xb. Further, the absolute coordinates of the X-axis of the point pa _c is PX1, the absolute coordinates of the X-axis of the point pb since it is PX2, relative distance ΔPX between point pa _c and the point pb is PX2-PX1.

Further, a point moved by relative distance ΔPX from relative coordinates xb of the map side distance test point pb is taken as PA. Distance difference Δx between the relative coordinate xa _c relative coordinates and trajectory space distance test point pa _c of this point PA is a length shown in FIG. 10.

The distance difference Δx the relative distance ΔPX and the map-space distance test point pb and trajectory side distance test in relative coordinates between the map-space distance test point pb and trajectory space distance test point pa _c in the absolute coordinate system it represents the difference between the distance between the point pa _c. In other words, it represents the error of the scale of the relative coordinate system when the absolute coordinate system is the correct answer.

  If the determination in step S10 is NO, the process of FIG. 7 is ended, and if YES, the process proceeds to step S12. In step S12, the probe trajectory Ac after trajectory correction is added to the reception map.

  More specifically, in step S12, the probe locus Ac after the trajectory correction is moved with respect to the stored reception map such that the probe locus Ac after the trajectory correction and the similar portion of the stored reception map overlap with each other. Combine in the direction of distance x.

  When combining the probe locus Ac after locus correction with the reception map, the portion where the probe locus Ac after locus correction and the reception map overlap in the direction of the movement distance axis averages each other's waveforms, for example. And combine. Alternatively, either one of the waveforms may be adopted as a combined reception map. Then, the reception map stored so far in the reception map database 43 is updated to the reception map obtained by combining the probe locus Ac after locus correction.

Summary of First Embodiment
As described above, according to the present embodiment described above, the wireless positioning device 30 mounted on the vehicle 50 has a probe trajectory that represents the relationship between the movement distance x and the RSSI when the vehicle 50 is traveling on the road. It generates and sends it to the management server 40.

  The control unit 44 of the management server 40 combines the probe trajectory transmitted from the wireless positioning device 30 and the reception map stored in the reception map database 43 based on the mutual matching part.

  FIG. 11 is an example in which the management server 40 receives the probe trajectory A and the probe trajectory J. It is assumed that these probe trajectories A and C have portions similar to the reception map B, and both steps S8 and S10 in FIG. 7 are YES.

  FIG. 12 shows an example in which probe trajectories Ac and Jc obtained by correcting the probe trajectories A and C are combined with the reception map B to form a new reception map. As shown in FIG. 12, in the present embodiment, by combining the probe trajectory with the reception map, the reception map spreads, so that it is possible to generate a reception map that is continuous over a wide area.

  In addition, since the receiving map before updating is such that the moving distance x can be associated with the absolute coordinates, the receiving map after combining is also associated with the moving distance x in the receiving map before updating and the absolute coordinates. By using the interpolation used, absolute coordinates can be determined with high accuracy.

  Further, in the present embodiment, in step S10, the accuracy of the relative coordinates of the probe trajectory Ac after trajectory correction is determined. If the determination in step S10 is YES, the probe trajectory Ac after trajectory correction (that is, after coordinate conversion) is added to the reception map, but if the determination in step S10 is NO, after trajectory correction The probe trajectory Ac of is not added to the reception map. As a result, only when the accuracy is good, the probe trajectory Ac after trajectory correction is added to the reception map, so even if the reception map of the added part is used, the absolute coordinates can be determined with high accuracy.

Second Embodiment
Next, a second embodiment will be described. In the following description of the second embodiment, elements having the same reference numerals as the reference numerals used so far are identical to the elements of the same reference numerals in the previous embodiments, unless otherwise stated. In addition, when only a part of the configuration is described, the embodiment described above can be applied to other parts of the configuration.

  In the first embodiment, the reception map is expanded in the longitudinal direction of the road, ie, in the direction along the road, whereas in the second embodiment, the reception map is expanded in the width direction of the road.

  In the second embodiment, as shown in FIG. 13, the wireless positioning device 130 includes the width direction position detection unit 131. More specifically, the width direction position detection unit 131 includes a camera, a radar, a LIDAR, etc., which is a lane marking detection apparatus for detecting a lane marking generally referred to as a white marking. From the relative position between the lane markings detected by the detection device and the host vehicle, the width direction position, which is the position of the host vehicle in the road width direction, is detected. The widthwise position is a relative position to the lane markings. The width direction position detection unit 131 outputs the detected width direction position to the control unit 36.

  As shown in FIG. 14, the control unit 36 includes a width direction trajectory generation unit 366 in addition to the configuration of the first embodiment. The width direction trajectory generation unit 366 generates a width direction position trajectory that represents the relationship between the movement distance x measured by the distance measurement unit 361 and the width direction position detected by the width direction position detection unit 131. The width direction locus generation unit 366 generates the width direction position locus in correspondence with the probe locus.

  The movement distance x is a relative position in the direction along the road, and in the second embodiment, the position in the width direction is also detected. In the second embodiment, the movement distance x is taken as the path direction position in order to make the distinction from the width direction position clear.

  FIG. 15 is a diagram conceptually showing the width direction position trajectory generated by the width direction trajectory generation unit 366. As shown in FIG. As shown in FIG. 15, when the vehicle travels on the road, the widthwise position changes to some extent. Then, if the widthwise position is different, the RSSI changes even if the route direction position is the same. Note that, as shown in FIG. 18, the actual width direction position locus is a map in which the path direction position is a horizontal axis and the width direction position is a vertical axis.

  In the second embodiment, the trajectory transmission control unit 364 of the control unit 36 transmits the width direction position trajectory generated by the width direction trajectory generation unit 366 to the management server 40 in addition to the probe trajectory generated by the trajectory generation unit 363. Do.

  In the second embodiment, as shown in FIG. 16, the control unit 44 of the management server 40 includes a trajectory acquisition unit 441, a coincidence determination unit 442, and a map update unit 443. In addition to the reception map, the widthwise position map is stored in the reception map database 43. Before describing the function of the control unit 44 in the second embodiment, the width direction position map will be described.

  The width direction position map is a map showing the relationship between the path direction position and the width direction position, as an example is shown in FIG. Further, the width direction position map is associated with the reception map. The association means that the widthwise position is determined from the widthwise position map and the RSSI is determined from the reception map at the same route direction position as illustrated in FIG.

  Next, the function of the control unit 44 will be described with reference to FIG. The locus acquisition unit 441 acquires the probe locus and the width direction position locus transmitted by the wireless positioning device 30 via the wide area wireless communication device 41.

  In the lower part of FIG. 18, the width direction position trajectory acquired by the trajectory acquisition unit 441 is shown in comparison with the width direction position map. Since the route direction position is a relative coordinate, even if the range of the route direction position of the width direction position trajectory is actually the same as the range of the route direction position of the width direction position map, As shown, the range of the path direction position of the width direction position track acquired by the path acquisition unit 441 may not coincide with the range of the path direction position of the width direction position map.

  The coincidence determination unit 442 moves the width direction position trajectory acquired by the trajectory acquisition unit 441 in the longitudinal direction of the road, so that the width direction position trajectory and the reception map have a portion where the width direction positions coincide with each other. To judge. In the lower part of FIG. 19, the width direction position locus is moved in the road longitudinal direction from the state of the lower part of FIG. 18, and the width direction position of part of the width direction position locus is made coincident with the width direction position of the reception map. It is a state. In addition, the road longitudinal direction is a left-right direction in FIG. 18, FIG.

  Furthermore, when there is a portion that matches the width direction position track and the width direction position map, the match determination unit 442 moves the probe track by the same amount as the width direction position track in the road longitudinal direction. Then, it is determined whether or not the probe trajectory after movement and the reception map have a coincident portion.

  The upper diagram of FIG. 18 illustrates the probe trajectory acquired by the trajectory acquisition unit 441 in comparison with the reception map. Actually, even if there is a coincident portion between the probe trajectory and the reception map, as shown in the upper view of FIG. 18, the coincident portion between the probe trajectory acquired by the trajectory acquisition unit 441 and the reception map is Sometimes it does not exist.

  The upper diagram of FIG. 19 is a diagram in which the probe trajectory is moved in the longitudinal direction of the road by the same amount as the width direction position trajectory. In the upper part of FIG. 19, the shapes of the probe trajectory and the reception map coincide with each other in a range encircled by a broken line circle.

  When the match determination unit 442 determines that the width direction position trajectory and the width direction position map have a match with each other and the probe trajectory and the reception map also have a match with each other, the map update unit 443 determines that The reception map stored in the reception map database 43 is updated.

  In the case of updating the reception map, the state shown in FIG. 19, that is, the state in which the width direction position track and the width direction position map coincide in the coincident portion, and the probe trajectory and the reception map coincide in the coincident portion. In this state, the widthwise position trajectory is coupled to the widthwise position map, and the probe trajectory is coupled to the reception map. Then, the width direction position map and the reception map stored in the reception map database 43 are updated to the width direction position map and the reception map after combination.

  According to the second embodiment, since the reception map can be extended in the width direction of the road, it is possible to generate a reception map that is wide in the width direction of the road.

Third Embodiment
The hardware configuration of the third embodiment is the same as that of the second embodiment, and the control unit 44 of the management server 40 has the function shown in FIG. However, in addition to the function of the second embodiment, the map updating unit 443 further includes a function of creating the width direction reception map WR.

  The processing executed by the map updating unit 443 in the third embodiment will be described below focusing on the function of creating the width direction reception map WR.

  In the lower part of FIG. 20, the reception maps E1, F1, G1, H1 are shown, and in the upper part, width direction position maps E2, F2, G2, H2 corresponding to the reception maps E1, F1, G1, H1 respectively. Is shown.

  In the example of FIG. 20, the reception map E1 and the width direction position map E2 are stored in advance in the reception map database 43. The reception maps F1, G1 and H1 are obtained by using the probe trajectory as the reception map, and the width direction position maps F2, G2 and H2 are obtained by using the width direction position trajectory as the width direction position map.

  The width direction position map F2 has the same width direction position in the width direction position map E2 and the area E2F2, and the reception map F1 has the same shape as the reception map E1 in the area E1F1 whose path direction position is the same as the area E2F2. Match. Therefore, the probe locus before forming the reception map F1 and the width direction position map F2 and the width direction position locus are set as the reception map F1 and the width direction position map F2.

  Similarly, in the width direction position map G2, the position in the width direction coincides between the width direction position map E2 and the area E2G2, and the reception map G1 is the area E1G1 whose position in the path direction is the same as the area E2G2 with the reception map E1. The shapes match each other. Therefore, the probe locus before forming the reception map G1 and the width direction position map G2 and the width direction position locus are set as the reception map G1 and the width direction position map G2.

  In the widthwise position map H2, the widthwise position of the widthwise position map F2 matches the widthwise position of the area F2H2, and the reception map H1 is mutually adjacent to the reception map F1 in the area F1H1 whose pathwise position is the same as the area F2H2. The shapes match. Therefore, the probe locus before forming the reception map H1 and the width direction position map H2 and the width direction position locus are set as the reception map G1 and the width direction position map G2.

  Since the width direction position locus and the probe locus before forming the width direction position map H2 and the reception map H1 are in agreement with the width direction position map F2 and the reception map F1 which are not initially stored in the reception map database 43, The width direction position map H2 and the reception map H1 are used. Thus, the width direction position map and the reception map can be expanded successively.

  The above processing is the same as in the map updating unit 443 of the second embodiment. Furthermore, the map updating unit 443 of the third embodiment creates the width direction reception map WR.

  The condition for creating the width direction reception map WR is that the width direction position is equal to or less than the preset interpolation upper limit pitch at the same route direction position in the plurality of width direction position maps stored in the reception map database 43 There are two points in the widthwise direction. The interpolation upper limit pitch is set in consideration of the interpolation method and interpolation accuracy. As an example, the interpolation upper limit pitch is 1⁄8, 1⁄4, 1⁄2, etc. of the wavelength of the radio wave received by the wireless communication device 31.

  When the condition for creating the width direction reception map WR is satisfied, the width direction position map including the two width direction positions which are equal to or less than the interpolation upper limit pitch is determined. In FIG. 20, x2 is shown as the route direction position where the condition for creating the width direction reception map WR is satisfied.

  At the route direction position x2, conditions for creating the width direction reception map WR are satisfied between the points pe and pf, between the points pf and pg, and between the points pg and ph. Therefore, the width direction position map including two width direction positions below the interpolation upper limit pitch has width direction position maps E2 and F2 as corresponding between points pe and pf, and points pf and pg There are width direction position maps F2 and G2 as corresponding to and width direction position maps F2 and G2 as corresponding between points pg and ph.

  In this way, when the width direction position map including the two width direction positions below the interpolation upper limit pitch is determined, the points of the two width direction positions below the interpolation upper limit pitch are respectively included. Interpolate the RSSI in the received map.

  FIG. 21 shows the relationship between the position in the width direction of points pe, pf, pg and ph and the RSSI. The width direction reception map WR shown in FIG.

  In the third embodiment, the width direction reception map WR is created. By using this width direction reception map WR together with the reception map, a two-dimensional reception map is obtained. Therefore, the current position of the vehicle can be determined two-dimensionally.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, The following modification is also contained in the technical scope of this invention, Furthermore, a summary is described in addition to the following. Various modifications can be made without departing from the scope of the invention.

<Modification 1>
For example, although the positioning part 34 of the above-mentioned embodiment was provided with the GNSS receiver and detected the absolute coordinate of the present position based on the signal which the GNSS receiver received, it is not restricted to this. The positioning unit includes a camera for photographing the periphery of the vehicle, a collating unit for analyzing an image photographed by the camera and collating with a peripheral image stored in advance, and a camera for photographing the image from a collation result collated by the collating unit The configuration may include a position, that is, a determination unit that determines absolute coordinates of the current position. In this case, a signal representing an image captured by a camera is positioning information.

  Also, in place of using a camera, LIDAR is used, and in place of a prestored peripheral image, a prestored 3D map is used, and a 3D map created from LIDAR measurement results and a prestored 3D map And the absolute coordinates of the current position may be determined. In this case, the signal detected by LIDAR is positioning information.

  The positioning unit may correct the current position measured from the signal received by the GNSS receiver by map matching to determine the absolute coordinates of the current position.

<Modification 2>
Instead of the RSSI, the arrival angle of TOF or radio wave may be used as a reception state indicator.

<Modification 3>
In the above-described embodiment, the reception map database 43 is included in the management server 40, and the control unit 44 of the management server 40 updates the reception map database 43. However, the reception map database 43 is included in the wireless positioning device 30. The control unit 36 of the wireless positioning device 30 may update the reception map database 43.

<Modification 4>
In the embodiment described above, correction with the distance between origin C and correction with the enlargement / reduction coefficient d are performed as locus correction, but only one of correction with the distance C between origin and correction with the enlargement / reduction coefficient d is performed It is also good.

10: Wireless positioning system 20: Base station 30: Wireless positioning device 31: Wireless communication device 32: Vehicle speed sensor 33: Wide area wireless communication device 34: Positioning unit 35: Memory 36: Control unit 37: CPU 38: ROM 39: RAM 40 : Management server 41: Wide area wireless communication device 42: Storage unit 43: Reception map database 44: Control unit 45: CPU 46: ROM 47: RAM 50: Vehicle 130: Wireless positioning device 131: Width direction position detection unit 361: Distance measurement Unit 362: Index acquisition unit 363: Trajectory generation unit 364: Trajectory transmission control unit 365: Position estimation unit 366: Width direction trajectory generation unit 441: Trajectory acquisition unit 442: Match determination unit 443: Map update unit

Claims (8)

It represents a change in the reception state indicator indicating the reception state of the radio wave when the radio wave from the base station is received on the path with respect to the position in the direction along the path along which the mobile body can move. A wireless positioning map generation system for generating a reception map capable of representing the position in the different direction in a positioning target coordinate system,
A storage unit (42) which stores the reception map in a rewritable manner;
A distance measuring unit (361) for measuring the moving distance of the moving body;
An indicator measurement unit (31) that receives radio waves from the base station and measures the reception condition indicator sequentially when the mobile unit is moving;
A trajectory generation unit (363) for generating a reception state trajectory representing a relationship between the movement distance measured by the distance measurement unit and the reception state indicator measured by the index measurement unit;
The reception map stored in the storage unit is generated by combining the reception state trajectory generated by the trajectory generation unit and the reception map stored in the storage unit based on the mutually matching parts. A map updating unit (S2, S4, S6, S12, 433) to be updated ;
The map update unit combines the reception state trajectory generated by the trajectory generation unit and the reception map stored in the storage unit in a direction along the route based on a mutual matching portion. The reception map stored in the storage unit is updated, and the reception state trajectory generated by the trajectory generation unit is at least one of relative movement and scaling of the direction of the movement distance. While performing certain trajectory correction, if it is determined that the reception state trajectory and the reception map stored in the storage unit match each other, and it is determined that there is the same portion, the reception after the trajectory correction is performed Combining a state trajectory with the reception map stored in the storage unit;
The reception state trajectory includes a trajectory side distance test point at which the relative distance in the positioning target coordinate system from the map side distance test point which is a point on the reception map stored in the storage unit can be determined. A test point judgment unit (S8) that judges whether or not
When the test point determination unit determines that there is the trajectory side distance test point, the relative distance from the relative coordinates of the map side distance test point after performing the trajectory correction on the reception state trajectory And a distance difference determination unit (S10) for determining whether the distance difference between the relative coordinates of the point moved by only the relative coordinates of the trajectory side distance test point is within a predetermined range,
The map updating unit updates the reception map stored in the storage unit based on the fact that the distance difference determining unit determines that the distance difference is within the predetermined range, and determines the distance difference. The wireless positioning map generation system, wherein the unit does not update the reception map stored in the storage unit based on the determination that the distance difference is not within the predetermined range. In claim 1,
And a positioning unit (34) configured to measure positioning target coordinates of the mobile unit based on preset positioning information other than the reception map.
When the locus generation unit can determine the positioning object coordinates at any one of the movement distances included in the reception state trajectory based on the positioning object coordinates measured by the positioning unit, Associating the movement distance of the trajectory with the positioning target coordinates;
When the positioning target coordinates are associated with the movement distance of the reception state trajectory, the map updating unit is based on the positioning object coordinates associated with the movement distance of the reception state trajectory. Determining the position of the reception state trajectory with respect to the reception map, and determining the presence or absence of a matching portion between the reception state trajectory and the reception map stored in the storage unit. Map generation system. It represents a change in the reception state indicator indicating the reception state of the radio wave when the radio wave from the base station is received on the path with respect to the position in the direction along the path along which the mobile body can move. A wireless positioning map generation system for generating a reception map capable of representing the position in the different direction in a positioning target coordinate system,
A storage unit (42) which stores the reception map in a rewritable manner;
A distance measuring unit (361) for measuring the moving distance of the moving body;
An indicator measurement unit (31) that receives radio waves from the base station and measures the reception condition indicator sequentially when the mobile unit is moving;
A trajectory generation unit (363) for generating a reception state trajectory representing a relationship between the movement distance measured by the distance measurement unit and the reception state indicator measured by the index measurement unit;
The reception map stored in the storage unit is generated by combining the reception state trajectory generated by the trajectory generation unit and the reception map stored in the storage unit based on the mutually matching parts. A map updating unit (S2, S4, S6, S12, 433) to be updated;
The moving body is a vehicle,
In addition to the reception map, a route direction position which is a position in a direction along the route on the reception map, and a width on the road where the reception condition index corresponding to the route direction position on the reception map can be measured A wireless positioning map generation system for generating a width direction position map in which a direction position and a direction position are associated,
The storage unit stores the width direction position map in addition to the reception map,
A width direction position detection unit (131) for detecting the width direction position of the vehicle;
A width direction locus generation unit (366) for generating a width direction position locus indicating a relationship between the movement distance measured by the distance measurement unit and the width direction position detected by the width direction position detection unit;
By moving the width direction position trajectory generated by the width direction trajectory generation unit in the longitudinal direction of the road, and moving the reception state trajectory by the same amount as the width direction position trajectory in the longitudinal direction of the road A coincidence judging unit (432) for judging whether the widthwise position locus and the widthwise position map produce a coincident portion with each other and the reception state locus and the reception map also produce a coincident portion with each other Equipped with
In the map update unit (433), the match determination unit causes the width direction position track and the width direction position map to have a match portion with each other, and the reception state trajectory and the reception map also match each other portion Are combined with the width direction position map in a state in which the width direction position trajectory and the width direction position map coincide in the matching portion, and the storage unit Updating the width direction position map stored in the memory, and combining the reception state locus in the state where the reception state locus and the reception map coincide in the matching portion with the reception map and storing the same in the storage unit A wireless positioning map generation system, characterized in that the reception map being updated is updated. In claim 3 ,
The map update unit combines the reception state trajectory generated by the trajectory generation unit and the reception map stored in the storage unit in a direction along the route based on a mutual matching portion. And updating the reception map stored in the storage unit. In claim 4 ,
The map update unit performs the trajectory correction that is at least one of relative movement and scaling of the direction of the movement distance, while performing the trajectory correction of the reception state trajectory generated by the trajectory generation unit, and the reception state trajectory and the storage unit If it is determined that there is a match between the reception maps stored in the memory, and if it is determined that there is the match, the reception state trajectory after trajectory correction is stored in the storage unit in the reception state trajectory. A map generation system for wireless positioning, characterized in that it is coupled to. In claim 5 ,
And a positioning unit (34) configured to measure positioning target coordinates of the mobile unit based on preset positioning information other than the reception map.
When the locus generation unit can determine the positioning object coordinates at any one of the movement distances included in the reception state trajectory based on the positioning object coordinates measured by the positioning unit, Associating the movement distance of the trajectory with the positioning target coordinates;
When the positioning target coordinates are associated with the movement distance of the reception state trajectory, the map updating unit is based on the positioning object coordinates associated with the movement distance of the reception state trajectory. Determining the position of the reception state trajectory with respect to the reception map, and determining the presence or absence of a matching portion between the reception state trajectory and the reception map stored in the storage unit. Map generation system. In claim 5 or 6 ,
The reception state trajectory includes a trajectory side distance test point at which the relative distance in the positioning target coordinate system from the map side distance test point which is a point on the reception map stored in the storage unit can be determined. A test point judgment unit (S8) that judges whether or not
When the test point determination unit determines that there is the trajectory side distance test point, the relative distance from the relative coordinates of the map side distance test point after performing the trajectory correction on the reception state trajectory And a distance difference determination unit (S10) for determining whether the distance difference between the relative coordinates of the point moved by only the relative coordinates of the trajectory side distance test point is within a predetermined range,
The map updating unit updates the reception map stored in the storage unit based on the fact that the distance difference determining unit determines that the distance difference is within the predetermined range, and determines the distance difference. The wireless positioning map generation system, wherein the unit does not update the reception map stored in the storage unit based on the determination that the distance difference is not within the predetermined range. In any one of claims 3 to 7 ,
The map updating unit is configured such that, in the width direction position map stored in the storage unit, two width direction positions where the width direction position is equal to or less than a preset interpolation upper limit pitch at the same route direction position If there is a point, the reception state index in the reception map including the two points in the widthwise position which are equal to or less than the interpolation upper limit pitch is interpolated to obtain the reception with respect to the widthwise position. A map generation system for wireless positioning, characterized in that a width direction reception map representing a status index is created.

Images